Late-onset transconjunctival oozing and point leak of aqueous humor from filtering bleb after trabeculectomy

Abstract

To estimate the prevalence and identify factors related to late-onset transconjunctival aqueous oozing and point leak from functioning blebs after trabeculectomy with 5-fluorouracil (5-FU) or mitomycin C. Cross-sectional study. The study took place at the outpatient clinic of the Department of Ophthalmology, University of Tokyo Graduate School of Medicine (Tokyo, Japan). Four hundred three consecutive patients (403 eyes) with functional blebs at least 3 months after previously performed trabeculectomy were examined between December 1997 and February 1998. The Seidel test was performed with extended observation up to 15 seconds. Oozing was identified as transconjunctival aqueous egress without interruption of the conjunctival tissue or aqueous stream on the bleb wall. Logistic regression analyses of oozing and point leak in 331 eyes with an avascular area were performed using independent variables, including age, gender, glaucoma diagnosis, prior incisional surgery, antimetabolite use, combined cataract surgery, postoperative follow-up period, intraocular pressure (IOP), concurrent glaucoma therapy, bleb size, and avascular area size. Of 403 eyes, 48 eyes (11.9%) had oozing and 8 eyes (2.0%) had point leak. Intraocular pressure was significantly lower and an avascular area was more frequent in eyes with oozing or leak than in eyes without (P <.001). Logistic regression analysis revealed that oozing was significantly more common after use of 5-FU than mitomycin C (P =.024), whereas point leak was associated with a larger avascular area (P =.045). After trabeculectomy with antimetabolites, transconjunctival oozing is much more frequent than point leak. Oozing was significantly associated with the use of 5-FU and point leak with a larger avascular area in the bleb.